Thank you so much to everyone who has donated to the atheist bus campaign. As I write this, the total has just broken £83,000 (without Gift Aid) – a truly amazing amount to raise in just two days (even the donation website, JustGiving, told us they've never experienced this much support for a campaign before!). You've helped us hit the national news headlines, give atheists more of a voice, and generate debate on TV, radio and newspapers throughout the world. It couldn't have happened without you, and we're extremely grateful for all your support.

There's been an exciting level of debate about the campaign. Lots of you have asked why the word "probably" is included in the ad slogan, and stated that you'd prefer the wording to read "There's no God". While I fully understand this view, there's a vital reason for the "probably"'s inclusion: as with the Carlsberg ads, it's likely to get us around the advertising regulations (specifically points 3.1, 3.2, 5.1, 8.1, 9.1 and 11.1 in the general rules of the CAP Code, which regulates non-broadcast adverts in the UK). In my view, neither version of the slogan breaches the code, but CAP has advised that "the inclusion of the word 'probably' makes it less likely to cause offence, and therefore be in breach of the Advertising Code."

There's another reason I'm keen on the "probably": it means the slogan is more accurate, as even though there's no scientific evidence at all for God's existence, it's also impossible to prove that God doesn't exist (or that anything doesn't). As Richard Dawkins states in The God Delusion, saying "there's no God" is taking a "faith" position. He writes: "Atheists do not have faith; and reason alone could not propel one to total conviction that anything definitely does not exist". His choice of words in the book is "almost certainly"; but while this is closer to what most atheists believe, "probably" is shorter and catchier, which is helpful for advertising. I also think the word is more lighthearted, and somehow makes the message more positive.

Many people have asked how the extra funds are going to be used. While everyone on the campaign team is elated at the amount raised, we genuinely never expected the campaign to skyrocket like this, and had only planned to use any extra money to buy small ads inside buses. We're hoping to run the campaign throughout the UK, but outside London we may have to think about using billboards and trains instead of buses, since the company Stagecoach runs many regional bus services and may not accept our adverts as its owner, Brian Souter, is an evangelical Christian.

Whatever happens, every penny of the total is going directly towards the atheist adverts. If you have an innovative idea about how we could advertise more effectively outside London, an atheist advertising slogan you like which we could use in future campaigns, or a thought about where we should take the campaign from here, please let us know – we'll read every comment.

Lastly, thank you once again to everyone who has given to the campaign, commented in a debate, blogged about it, linked to a site or story about it, joined the Facebook group, forwarded links to friends, or posted a funny, kind or supportive comment on the JustGiving page. Atheists have truly pulled together to make ourselves heard, and it's exciting to imagine what we could achieve in the future. The sky's the limit, and as one comment on the donation page said: "I hope this is just the beginning."